1. Field of the Invention
The present disclosure generally relates to medical systems and methods for repairing biological tissue. More particularly, the disclosure generally relates to a system and method for an implant system for repairing damaged tissue.
2. Description of the Relevant Art
The field of medical implants has resulted in the development of biocompatible scaffolds with for use in the repair of tissue. For example, the use of porous mesh plugs formed from hydroxy acid polymers has been used for healing bone imperfections. Implants have been described which are both biodegradable and bioresorbable templates. Scaffolds have been produced using vacuum foaming techniques. Implant requiring strength and rigidity (e.g., bone implants) have been formed from metals (e.g., stainless steel, titanium, titanium alloy, nickel, cobalt alloy), composite materials (e.g., composites of carbon, thermosetting resins) and ceramics (e.g., alumina, zirconia, hydroxyapatite). Problems still remain unsolved when using many of these materials: corrosion and fatigue for metals; low toughness and excessively high rigidity for ceramics; and interface destruction for composite materials of inorganic materials with organic polymer materials.
Other types of implants have been formed open cell porous biocompatible foams. Open cell porous biocompatible foams are recognized to have significant potential for use in the repair and regeneration of tissue. Early efforts in tissue repair focused on the use of biocompatible foam as porous plugs to fill voids in bone. An open cell foam of polyhydroxy acids with pores for the in-growth of blood vessels and cells have been previously described. The described foams have been reinforced with fibers, yarns, braids, knitted fabrics, scrims and the like. Unfortunately porous biocompatible foams have several inherent limitations. Foam implants are not easily loaded with biocompatible materials such that the materials are evenly distributed. Foams typically have to soak up the biological material and/or have the material injected directly into the foam implant. It is a difficult and/or time consuming process to evenly distribute biological material throughout many foam implants. This may be problematic during a surgical procedure where time is critical. In some instances foam implants may be pliable much like a sponge, which can cause problems with biological materials injected in the foam implant being expelled when a load is placed on implant compressing it. The biological materials may be expelled prematurely and/or to quickly in such an instance. Foam implants can be limited in the particle size of the biological material which can be loaded into the implant. In addition, when loads are applied to foam based implants, the latter collapse, disintegrate, and in may instances undergo significant plastic deformation, which prevents these loads from being communicated to the cells throughout all layers of the foam material.
Therefore, it is desirable to provide a biocompatible, bioabsorbable implant that provides a continuous gradient of morphological, structural and/or materials. Further, it is preferred that implant materials used in tissue engineering have a structure that provides a template that facilitates the retention of the majority of the cells infused, injected or applied and that are capable of transferring directional deformational loads to the cells which contributes to the proliferation and differentiation of cells, ultimately resulting in the regeneration of functional tissue.